As Washington continues to lobby China to put more pressure on Pyongyang, Beijing clearly stated its opposition to any form of cyberattack but has yet to make a final judgment regarding the hacking of US-based Sony Pictures Entertainment.

There may be a number of possible technical explanations behind the attack, experts said, and it is still too early for Beijing to form any conclusion before Washington provides tangible evidence.

US Secretary of State John Kerry briefed Foreign Minister Wang Yi on Washington's viewpoints about the cyberattack in a telephone conversation on Sunday.

China "opposes any manner of cyberattacks and cyberterrorism", the minister said, and added that Beijing is also "opposed to any country or any individual that launches cyberattacks via facilities in another country".

US media speculated last week that hackers could have taken advantage of the greater bandwidth in China to launch their attack.

"China is willing to embark on constructive cooperation with the international community to safeguard the peace and security of cyberspace on the basis of mutual respect and mutual trust," Foreign Ministry spokeswoman Hua Chunying said in Beijing on Monday.

The US Federal Bureau of Investigation claimed on Friday that investigators had found what it called "enough information" to conclude that the Democratic People's Republic of Korea was "responsible" for the attack.

Zuo Xiaodong, vice-president of China Information Security Research Institute, said Washington's decision to make public its accusations without offering any tangible evidence "may run against the spirit of science".

"As for servers of a private business, which are usually more vulnerable than governmental ones, the hacking may have been done by hackers acting on their own rather than a cyber army," Zuo said.

Earlier this month, Sony decided to cancel the scheduled Thursday release of the comedy movie The Interview, which depicts an assassination attempt on Kim Jong Un, leader of the DPRK.

In November, hackers accessed the Sony computer system and released some of the stolen data. The hackers threatened to disclose more Sony data if it went ahead with the movie's release.

US President Barack Obama said in a CNN interview aired on Sunday that he regards the hacking as an "act of cyber vandalism" rather than an "act of war," while reiterating the US will respond proportionately.